December 17, 2009


The long-awaited and highly anticipated Avatar, written, directed, and produced by James Cameron and released by Twentieth Century Fox, pushes digital filmmaking into new worlds. It will immerse audiences in an alien environment, one created entirely with computer graphics and projected, in theaters so equipped, in stereo 3D. Cameron used a Pace Fusion 3D camera to film the live-action segments, but they comprise a small percentage of the film. Weta Digital created the alien planet Pandora and the CG characters and creatures that inhabit it, animating the characters using data from actors’ performances on motion-capture sets. Will it have the same impact on visual effects as did Cameron’s earlier films?
“It certainly changed the way we do things,” says Joe Letteri, senior visual effects supervisor at Weta Digital, who was a CG artist at Industrial Light & Magic on Cameron’s The Abyss. “We had to go through a complete re-tooling and re-architecting.”

In particular, Letteri notes, the studio revamped systems for real-time facial motion capture and muscles, created methods for growing a rain forest in which most of the movie takes place, implemented new lighting techniques, built a compositing pipeline to handle stereo 3D, and more. “We could not allow ourselves to cheat anything,” he says. “Everything had to be done correctly; there was no place to hide.”

In the film, Jake Sully (actor Sam Worthington), a paraplegic war veteran, is given the opportunity to inhabit the athletic body of an avatar. He opts in. His avatar is an alien, a Na’vi, a race of humanoids that populate the planet Pandora. He, like all Na’vi, is blue. A 10-foot-tall biped with a stretched, cat-like body. Almond-shaped eyes. Tail. Pointed ears. Through his avatar, Jake immigrates to Pandora, a lush planet filled with waterfalls, jungles, and six-legged creatures, some of which fly. There he meets the beautiful Neytiri (actor Zoe Saldana) and assimilates into the Na’vian culture. Everything on Pandora—every plant, creature, and character—is digital, created by artists using computer graphics tools and moved by animators working with keyframe and motion-capture data.

To read Barbara Robertson’s entire feature detailing the in-depth creation of Avatar, see the December issue of Computer Graphics World.